.app{
	width: 100%;
	height: 100vh;
	background-color: #fff;
	position: relative;
	display: flex;
	justify-content: center;
	align-items: center;
}
.btn83{
	width: 120px;
	height: 48px;
	font-size: 16px;
	font-weight: bold;
	color: #fff;
	letter-spacing: 2px;
	position: relative;
	border: none;
	outline: none;
	background-color: #25c10f;
	border-radius: 7px;
	cursor: pointer;
	box-shadow: 0 0 0 4px #15521a;
	transition: all 0.1s linear;
}
.btn83:after{
	content: 'BUTTON';
	width: 100%;
	font-size: 16px;
	font-weight: bold;
	color: #155329;
	letter-spacing: 2px;
	position: absolute;
	left: 0;
	opacity: 1;
	transition: all 0.3s linear;
}
.btn83:hover:after{
	opacity: 0;
	transform: translateY(-20px);
}
.btn83:active{
	transform: scale(0.99);
	box-shadow: 0 0 0 2px #15521a;
}